US8780476B2 - Systems and methods for controlled wedge spacing in a storage device - Google Patents
Systems and methods for controlled wedge spacing in a storage device Download PDFInfo
- Publication number
- US8780476B2 US8780476B2 US13/242,983 US201113242983A US8780476B2 US 8780476 B2 US8780476 B2 US 8780476B2 US 201113242983 A US201113242983 A US 201113242983A US 8780476 B2 US8780476 B2 US 8780476B2
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- US
- United States
- Prior art keywords
- clock
- phase
- data
- domain
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- Prior art date
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Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/14—Digital recording or reproducing using self-clocking codes
- G11B20/1403—Digital recording or reproducing using self-clocking codes characterised by the use of two levels
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10222—Improvement or modification of read or write signals clock-related aspects, e.g. phase or frequency adjustment or bit synchronisation
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/596—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks
- G11B5/59633—Servo formatting
- G11B5/5965—Embedded servo format
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- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Signal Processing For Digital Recording And Reproducing (AREA)
- Moving Of The Head To Find And Align With The Track (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
Abstract
Description
A
The following equation yields raw data clock 383:
As
where the Distance is the number of periods of
Temporary Value = Old Accumulator + |
If ( |
{ |
Old Accumulator = |
If (Temporary Value < Denominator Value 386) |
{ |
|
} |
Else |
{ |
|
} |
} |
Of note, as with the above mentioned servo clock multiplier and data clock multiplier,
Cumulative Data | ||||
Clock Phase | ||||
Servo | Modified | Adjustment Applied | ||
Wedge | Output | to Phase Adjusted | ||
| Modulus Output | 391 | 395 | |
1 | 14/34 | 26/64 | 26/64 | |
2 | 28/34 | 53/64 | 53/64 | |
3 | 8/34 (Wrapped Around) | 15/64 | 1 and 15/64 | |
4 | 22/34 | 41/64 | 1 and 41/64 | |
5 | 2/34 (Wrapped Around) | 4/64 | 2 and 4/64 | |
6 | 16/34 | 30/64 | 2 and 30/64 | |
. . . | . . . | . . . | . . . | |
By using such fractional locking, a phase lock can be achieved for phase adjusted
Both a servo clock and a raw data clock are generated from a reference clock based upon the frequency error percentage (block 520). The servo clock may be generated by multiplying the reference clock by a value corresponding to the frequency error percentage as shown in the following equation:
Servo Clock=Servo Clock Multiplier*[Reference Clock*(1+Frequency Error Percentage)].
The reference clock is phase and frequency aligned with a clock generated using information from servo wedges. The servo clock multiplier is a defined multiple of the frequency of the reference clock that yields the servo clock. In some cases, the servo clock multiplier may be variable through programming or may be fixed. For example, where a 1.02 GHz clock is desired for
The following equation yields the raw data clock:
Raw Data Clock=Data Clock Multiplier*[Reference Clock*(1+Frequency Error Percentage)*Data to Servo Clock Ratio].
As both the servo clock and the raw data clock are generated from the same reference clock, disk clock lock is achieved.
Claims (20)
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/242,983 US8780476B2 (en) | 2011-09-23 | 2011-09-23 | Systems and methods for controlled wedge spacing in a storage device |
CN201210027723.1A CN103021436B (en) | 2011-09-23 | 2012-01-30 | System and method for wedge shape interval in check in storage device |
JP2012068651A JP5840546B2 (en) | 2011-09-23 | 2012-03-26 | System and method for controlled wedge spacing in storage devices |
KR1020120080177A KR20130032820A (en) | 2011-09-23 | 2012-07-23 | Systems and methods for controlled wedge spacing in a storage device |
TW101126475A TW201329963A (en) | 2011-09-23 | 2012-07-23 | Systems and methods for controlled wedge spacing in a storage device |
EP12178169.4A EP2573771A3 (en) | 2011-09-23 | 2012-07-27 | Systems and methods for controlling wedge spacing in a storage device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/242,983 US8780476B2 (en) | 2011-09-23 | 2011-09-23 | Systems and methods for controlled wedge spacing in a storage device |
Publications (2)
Publication Number | Publication Date |
---|---|
US20130077188A1 US20130077188A1 (en) | 2013-03-28 |
US8780476B2 true US8780476B2 (en) | 2014-07-15 |
Family
ID=47076049
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/242,983 Expired - Fee Related US8780476B2 (en) | 2011-09-23 | 2011-09-23 | Systems and methods for controlled wedge spacing in a storage device |
Country Status (6)
Country | Link |
---|---|
US (1) | US8780476B2 (en) |
EP (1) | EP2573771A3 (en) |
JP (1) | JP5840546B2 (en) |
KR (1) | KR20130032820A (en) |
CN (1) | CN103021436B (en) |
TW (1) | TW201329963A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8879186B1 (en) * | 2014-08-19 | 2014-11-04 | Avago Technologies General Ip (Singapore) Pte. Ltd. | Fast flaw scan for multiple sensor systems |
US20150279398A1 (en) * | 2014-03-28 | 2015-10-01 | Lsi Corporation | Locking a Disk-Locked Clock Using Timestamps of Successive Servo Address Marks in a Spiral Servo Track |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9749125B2 (en) * | 2014-12-12 | 2017-08-29 | Analog Devices Global | Apparatus and method for clock generation |
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US20150279398A1 (en) * | 2014-03-28 | 2015-10-01 | Lsi Corporation | Locking a Disk-Locked Clock Using Timestamps of Successive Servo Address Marks in a Spiral Servo Track |
US9280995B2 (en) * | 2014-03-28 | 2016-03-08 | Avago Technologies General Ip (Singapore) Pte. Ltd. | Locking a disk-locked clock using timestamps of successive servo address marks in a spiral servo track |
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KR20130032820A (en) | 2013-04-02 |
CN103021436B (en) | 2017-03-01 |
JP2013069398A (en) | 2013-04-18 |
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US20130077188A1 (en) | 2013-03-28 |
EP2573771A3 (en) | 2014-11-05 |
CN103021436A (en) | 2013-04-03 |
TW201329963A (en) | 2013-07-16 |
EP2573771A2 (en) | 2013-03-27 |
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